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  Golang学习笔记（三）——数据类型转换
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<p>作者: 杰克小麻雀<br>原文链接: <a target="_blank" rel="noopener" href="https://blog.csdn.net/yushuaigee/article/details/106305233">https://blog.csdn.net/yushuaigee/article/details/106305233</a></p>
</blockquote>
<h2 id="强制类型转换"><a href="#强制类型转换" class="headerlink" title="强制类型转换"></a>强制类型转换</h2><p>类似于其他语言，Go语言也支持强制类型转换：</p>
<p><img src="https://cdn.jsdelivr.net/gh/yushuaige/myblog@master/img/20200523205009481.png" alt="20200523205009481.png"></p>
<p>但是只有相同底层类型的变量之间可以进行相互转换（如将 int16 和 int32 相互转换，float 类型和 int 类型相互转换），不同底层类型的变量相互转换时会引发编译错误（如 bool 类型和 int 类型，string 与 int 类型之间的转换）： </p>
<p><img src="https://cdn.jsdelivr.net/gh/yushuaige/myblog@master/img/20200523200617332.png" alt="20200523200617332.png"></p>
<h2 id="字符串和数值类型的相互转换-strconv"><a href="#字符串和数值类型的相互转换-strconv" class="headerlink" title="字符串和数值类型的相互转换 (strconv)"></a>字符串和数值类型的相互转换 (strconv)</h2><p>如果需要string、int、int64、float 等数据类型之间的转换功能，可以使用标准包中的 strconv 包。</p>
<p>strconv 包中常用的函数包括 <strong>Atoi()**、</strong>Itia()<strong>、</strong>parse** 系列函数、<strong>format **系列函数、</strong>append **系列函数等。</p>
<h3 id="Itoa-：整型转字符串"><a href="#Itoa-：整型转字符串" class="headerlink" title="Itoa()：整型转字符串"></a>Itoa()：整型转字符串</h3><p>integer to alphanumeric</p>
<p>函数原型：</p>
<p><code>func Itoa(i int) string    </code></p>
<p>输入 int，输出 string</p>
<figure class="highlight go"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> main</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> (</span><br><span class="line">	<span class="string">&quot;fmt&quot;</span></span><br><span class="line">	<span class="string">&quot;strconv&quot;</span></span><br><span class="line">)</span><br><span class="line"></span><br><span class="line"><span class="function"><span class="keyword">func</span> <span class="title">main</span><span class="params">()</span></span> &#123;</span><br><span class="line">	num := <span class="number">100</span></span><br><span class="line">	str := strconv.Itoa(num)</span><br><span class="line">	fmt.Printf(<span class="string">&quot;type:%T value:%#v\n&quot;</span>, str, str)</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line"><span class="comment">//输出:</span></span><br><span class="line"><span class="comment">//type:string value:&quot;100&quot;</span></span><br></pre></td></tr></table></figure>
<h3 id="Atoi-：字符串转整型"><a href="#Atoi-：字符串转整型" class="headerlink" title="Atoi()：字符串转整型"></a>Atoi()：字符串转整型</h3><p>alphanumeric to integer</p>
<p>函数原型：</p>
<p><code>func Atoi(s string) (i int, err error)</code></p>
<p> 输入 string，输出 int 和 错误信息</p>
<figure class="highlight go"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> main</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> (</span><br><span class="line">	<span class="string">&quot;fmt&quot;</span></span><br><span class="line">	<span class="string">&quot;strconv&quot;</span></span><br><span class="line">)</span><br><span class="line"></span><br><span class="line"><span class="function"><span class="keyword">func</span> <span class="title">main</span><span class="params">()</span></span> &#123;</span><br><span class="line">	str1 := <span class="string">&quot;110&quot;</span></span><br><span class="line">	str2 := <span class="string">&quot;s100&quot;</span></span><br><span class="line">	num1, err := strconv.Atoi(str1)</span><br><span class="line">	<span class="keyword">if</span> err != <span class="literal">nil</span> &#123;</span><br><span class="line">		fmt.Printf(<span class="string">&quot;%v 转换失败！&quot;</span>, str1)</span><br><span class="line">	&#125; <span class="keyword">else</span> &#123;</span><br><span class="line">		fmt.Printf(<span class="string">&quot;type:%T value:%#v\n&quot;</span>, num1, num1)</span><br><span class="line">	&#125;</span><br><span class="line">	num2, err := strconv.Atoi(str2)</span><br><span class="line">	<span class="keyword">if</span> err != <span class="literal">nil</span> &#123;</span><br><span class="line">		fmt.Printf(<span class="string">&quot;%v 转换失败！&quot;</span>, str2)</span><br><span class="line">	&#125; <span class="keyword">else</span> &#123;</span><br><span class="line">		fmt.Printf(<span class="string">&quot;type:%T value:%#v\n&quot;</span>, num2, num2)</span><br><span class="line">	&#125;</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line"><span class="comment">//输出：</span></span><br><span class="line"><span class="comment">//type:int value:110</span></span><br><span class="line"><span class="comment">//s100 转换失败！</span></span><br></pre></td></tr></table></figure>
<h3 id="Parse-系列：str-转其他"><a href="#Parse-系列：str-转其他" class="headerlink" title="Parse 系列：str 转其他"></a>Parse 系列：str 转其他</h3><h4 id="ParseBool"><a href="#ParseBool" class="headerlink" title="ParseBool()"></a>ParseBool()</h4><p>函数原型：</p>
<p><code>func ParseBool(str string) (value bool, err error)</code></p>
<p>它只能接受 1、0、t、f、T、F、true、false、True、False、TRUE、FALSE，其它的值均返回错误。</p>
<figure class="highlight go"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> main</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> (</span><br><span class="line">	<span class="string">&quot;fmt&quot;</span></span><br><span class="line">	<span class="string">&quot;strconv&quot;</span></span><br><span class="line">)</span><br><span class="line"></span><br><span class="line"><span class="function"><span class="keyword">func</span> <span class="title">main</span><span class="params">()</span></span> &#123;</span><br><span class="line">	str1 := <span class="string">&quot;110&quot;</span></span><br><span class="line">	boo1, err := strconv.ParseBool(str1)</span><br><span class="line">	<span class="keyword">if</span> err != <span class="literal">nil</span> &#123;</span><br><span class="line">		fmt.Printf(<span class="string">&quot;str1: %v\n&quot;</span>, err)</span><br><span class="line">	&#125; <span class="keyword">else</span> &#123;</span><br><span class="line">		fmt.Println(boo1)</span><br><span class="line">	&#125;</span><br><span class="line">	str2 := <span class="string">&quot;t&quot;</span></span><br><span class="line">	boo2, err := strconv.ParseBool(str2)</span><br><span class="line">	<span class="keyword">if</span> err != <span class="literal">nil</span> &#123;</span><br><span class="line">		fmt.Printf(<span class="string">&quot;str2: %v\n&quot;</span>, err)</span><br><span class="line">	&#125; <span class="keyword">else</span> &#123;</span><br><span class="line">		fmt.Println(boo2)</span><br><span class="line">	&#125;</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line"><span class="comment">//输出：</span></span><br><span class="line"><span class="comment">//str1: strconv.ParseBool: parsing &quot;110&quot;: invalid syntax</span></span><br><span class="line"><span class="comment">//true</span></span><br></pre></td></tr></table></figure>
<h4 id="ParseInt"><a href="#ParseInt" class="headerlink" title="ParseInt()"></a>ParseInt()</h4><p>函数原型：</p>
<p><code>func ParseInt(s string, base int, bitSize int) (i int64, err error)</code></p>
<p>函数用于返回字符串表示的整数值，<strong>可以包含正负号</strong>。</p>
<p>参数说明：</p>
<ul>
<li>base 指定进制，取值范围是 2 到 36。如果 base 为 0，则会从字符串前置判断，“0x” 是 16 进制，“0” 是 8 进制，否则是 10 进制。</li>
<li>bitSize 指定结果必须能无溢出赋值的整数类型，0、8、16、32、64 分别代表 int、int8、int16、int32、int64。</li>
<li>返回的 err 是 *NumErr 类型的，如果语法有误，err.Error = ErrSyntax，如果结果超出类型范围 err.Error = ErrRange。<figure class="highlight go"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> main</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> (</span><br><span class="line">	<span class="string">&quot;fmt&quot;</span></span><br><span class="line">	<span class="string">&quot;strconv&quot;</span></span><br><span class="line">)</span><br><span class="line"></span><br><span class="line"><span class="function"><span class="keyword">func</span> <span class="title">main</span><span class="params">()</span></span> &#123;</span><br><span class="line">	str := <span class="string">&quot;-11&quot;</span></span><br><span class="line">	num, err := strconv.ParseInt(str, <span class="number">10</span>, <span class="number">0</span>)</span><br><span class="line">	<span class="keyword">if</span> err != <span class="literal">nil</span> &#123;</span><br><span class="line">		fmt.Println(err)</span><br><span class="line">	&#125; <span class="keyword">else</span> &#123;</span><br><span class="line">		fmt.Println(num)</span><br><span class="line">	&#125;</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line"><span class="comment">//输出：</span></span><br><span class="line"><span class="comment">//-11</span></span><br></pre></td></tr></table></figure>
<h4 id="ParseUint"><a href="#ParseUint" class="headerlink" title="ParseUint()"></a>ParseUint()</h4></li>
</ul>
<p>函数原型：</p>
<p><code>func ParseUint(s string, base int, bitSize int) (n uint64, err error)</code></p>
<p>函数用于返回字符串表示的整数值，但 ParseUint() 函数<strong>不接受正负号，用于无符号整型。</strong></p>
<p>参数说明：(同ParseInt())</p>
<ul>
<li>base 指定进制，取值范围是 2 到 36。如果 base 为 0，则会从字符串前置判断，“0x”是 16 进制，“0”是 8 进制，否则是 10 进制。</li>
<li>bitSize 指定结果必须能无溢出赋值的整数类型，0、8、16、32、64 分别代表 int、int8、int16、int32、int64。</li>
<li>返回的 err 是 *NumErr 类型的，如果语法有误，err.Error = ErrSyntax，如果结果超出类型范围 err.Error = ErrRange。<figure class="highlight go"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> main</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> (</span><br><span class="line">	<span class="string">&quot;fmt&quot;</span></span><br><span class="line">	<span class="string">&quot;strconv&quot;</span></span><br><span class="line">)</span><br><span class="line"></span><br><span class="line"><span class="function"><span class="keyword">func</span> <span class="title">main</span><span class="params">()</span></span> &#123;</span><br><span class="line">	str := <span class="string">&quot;11&quot;</span></span><br><span class="line">	num, err := strconv.ParseUint(str, <span class="number">10</span>, <span class="number">0</span>)</span><br><span class="line">	<span class="keyword">if</span> err != <span class="literal">nil</span> &#123;</span><br><span class="line">		fmt.Println(err)</span><br><span class="line">	&#125; <span class="keyword">else</span> &#123;</span><br><span class="line">		fmt.Println(num)</span><br><span class="line">	&#125;</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line"><span class="comment">//输出：</span></span><br><span class="line"><span class="comment">//11</span></span><br></pre></td></tr></table></figure>
<h4 id="ParseFloat"><a href="#ParseFloat" class="headerlink" title="ParseFloat()"></a>ParseFloat()</h4></li>
</ul>
<p>函数原型：</p>
<p><code>func ParseFloat(s string, bitSize int) (f float64, err error)</code></p>
<p>函数用于将一个表示浮点数的字符串转换为 float 类型。</p>
<p>参数说明：</p>
<ul>
<li>如果 s 合乎语法规则，函数会返回最为接近 s 表示值的一个浮点数（使用 IEEE754 规范舍入）。</li>
<li>bitSize 指定了返回值的类型，32 表示 float32，64 表示 float64；</li>
<li>返回值 err 是 *NumErr 类型的，如果语法有误 err.Error=ErrSyntax，如果返回值超出表示范围，返回值 f 为 ±Inf，err.Error= ErrRange。<figure class="highlight go"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> main</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> (</span><br><span class="line">	<span class="string">&quot;fmt&quot;</span></span><br><span class="line">	<span class="string">&quot;strconv&quot;</span></span><br><span class="line">)</span><br><span class="line"></span><br><span class="line"><span class="function"><span class="keyword">func</span> <span class="title">main</span><span class="params">()</span></span> &#123;</span><br><span class="line">	str := <span class="string">&quot;3.1415926&quot;</span></span><br><span class="line">	num, err := strconv.ParseFloat(str, <span class="number">64</span>)</span><br><span class="line">	<span class="keyword">if</span> err != <span class="literal">nil</span> &#123;</span><br><span class="line">		fmt.Println(err)</span><br><span class="line">	&#125; <span class="keyword">else</span> &#123;</span><br><span class="line">		fmt.Println(num)</span><br><span class="line">	&#125;</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line"><span class="comment">//输出：</span></span><br><span class="line"><span class="comment">//3.1415926</span></span><br></pre></td></tr></table></figure>
<h3 id="Format-系列：其他转-str"><a href="#Format-系列：其他转-str" class="headerlink" title="Format 系列：其他转 str"></a>Format 系列：其他转 str</h3></li>
</ul>
<h4 id="FormatBool"><a href="#FormatBool" class="headerlink" title="FormatBool()"></a>FormatBool()</h4><p>函数原型：</p>
<p><code>func FormatBool(b bool) string</code></p>
<p>函数可以将一个 bool 类型的值转换为对应的字符串类型。</p>
<figure class="highlight go"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> main</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> (</span><br><span class="line">	<span class="string">&quot;fmt&quot;</span></span><br><span class="line">	<span class="string">&quot;strconv&quot;</span></span><br><span class="line">)</span><br><span class="line"></span><br><span class="line"><span class="function"><span class="keyword">func</span> <span class="title">main</span><span class="params">()</span></span> &#123;</span><br><span class="line">	num := <span class="literal">true</span></span><br><span class="line">	str := strconv.FormatBool(num)</span><br><span class="line">	fmt.Printf(<span class="string">&quot;type:%T,value:%v\n &quot;</span>, str, str)</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line"><span class="comment">//输出：</span></span><br><span class="line"><span class="comment">//type:string,value:true</span></span><br></pre></td></tr></table></figure>
<h4 id="FormatInt"><a href="#FormatInt" class="headerlink" title="FormatInt()"></a>FormatInt()</h4><p>函数原型：</p>
<p><code>func FormatInt(i int64, base int) string</code></p>
<p>函数用于将整型数据转换成指定进制并以字符串的形式返回。</p>
<p>参数说明：</p>
<ul>
<li>参数 i 必须是 int64 类型，参数 base 必须在 2 到 36 之间，返回结果中会使用小写字母“a”到“z”表示大于 10 的数字。<figure class="highlight go"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> main</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> (</span><br><span class="line">	<span class="string">&quot;fmt&quot;</span></span><br><span class="line">	<span class="string">&quot;strconv&quot;</span></span><br><span class="line">)</span><br><span class="line"></span><br><span class="line"><span class="function"><span class="keyword">func</span> <span class="title">main</span><span class="params">()</span></span> &#123;</span><br><span class="line">	<span class="keyword">var</span> num <span class="keyword">int64</span> = <span class="number">100</span></span><br><span class="line">	str := strconv.FormatInt(num, <span class="number">16</span>)</span><br><span class="line">	fmt.Printf(<span class="string">&quot;type:%T,value:%v\n &quot;</span>, str, str)</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line"><span class="comment">//输出：</span></span><br><span class="line"><span class="comment">//type:string,value:64</span></span><br></pre></td></tr></table></figure>
<h4 id="FormatUint"><a href="#FormatUint" class="headerlink" title="FormatUint()"></a>FormatUint()</h4></li>
</ul>
<p>函数原型：</p>
<p><code>func FormatUint(i uint64, base int) string</code></p>
<p>函数用于将无符号的整型数据转换成指定进制并以字符串的形式返回。</p>
<p>参数说明：</p>
<ul>
<li>参数 i 必须是无符号的 uint64 类型，参数 base 必须在 2 到 36 之间，返回结果中会使用小写字母“a”到“z”表示大于 10 的数字。<figure class="highlight go"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> main</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> (</span><br><span class="line">	<span class="string">&quot;fmt&quot;</span></span><br><span class="line">	<span class="string">&quot;strconv&quot;</span></span><br><span class="line">)</span><br><span class="line"></span><br><span class="line"><span class="function"><span class="keyword">func</span> <span class="title">main</span><span class="params">()</span></span> &#123;</span><br><span class="line">	<span class="keyword">var</span> num <span class="keyword">uint64</span> = <span class="number">110</span></span><br><span class="line">	str := strconv.FormatUint(num, <span class="number">16</span>)</span><br><span class="line">	fmt.Printf(<span class="string">&quot;type:%T,value:%v\n &quot;</span>, str, str)</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line"><span class="comment">//输出：</span></span><br><span class="line"><span class="comment">//type:string,value:6e</span></span><br></pre></td></tr></table></figure>
<h4 id="FormatFloat"><a href="#FormatFloat" class="headerlink" title="FormatFloat()"></a>FormatFloat()</h4></li>
</ul>
<p>函数原型：</p>
<p><code>func FormatFloat(f float64, fmt byte, prec, bitSize int) string</code></p>
<p>函数用于将浮点数转换为字符串类型并以字符串的形式返回。</p>
<p>参数说明：</p>
<ul>
<li>bitSize 表示参数 f 的来源类型（32 表示 float32、64 表示 float64），会据此进行舍入。</li>
<li>fmt 表示格式，可以设置为“f”表示 -ddd.dddd、“b”表示 -ddddp±ddd，指数为二进制、“e”表示 -d.dddde±dd 十进制指数、“E”表示 -d.ddddE±dd 十进制指数、“g”表示指数很大时用“e”格式，否则“f”格式、“G”表示指数很大时用“E”格式，否则“f”格式。</li>
<li>prec 控制精度（排除指数部分）：当参数 fmt 为“f”、“e”、“E”时，它表示小数点后的数字个数；当参数 fmt 为“g”、“G”时，它控制总的数字个数。如果 prec 为 -1，则代表使用最少数量的、但又必需的数字来表示 f。<figure class="highlight go"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> main</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> (</span><br><span class="line">	<span class="string">&quot;fmt&quot;</span></span><br><span class="line">	<span class="string">&quot;strconv&quot;</span></span><br><span class="line">)</span><br><span class="line"></span><br><span class="line"><span class="function"><span class="keyword">func</span> <span class="title">main</span><span class="params">()</span></span> &#123;</span><br><span class="line">	<span class="keyword">var</span> num <span class="keyword">float64</span> = <span class="number">3.1415926</span></span><br><span class="line">	str := strconv.FormatFloat(num, <span class="string">&#x27;E&#x27;</span>, <span class="number">-1</span>, <span class="number">64</span>)</span><br><span class="line">	fmt.Printf(<span class="string">&quot;type:%T,value:%v\n &quot;</span>, str, str)</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line"><span class="comment">//输出：</span></span><br><span class="line"><span class="comment">//type:string,value:3.1415926E+00</span></span><br></pre></td></tr></table></figure>
<h3 id="Append-系列：其他转-str-后加到切片中"><a href="#Append-系列：其他转-str-后加到切片中" class="headerlink" title="Append 系列：其他转 str 后加到切片中"></a>Append 系列：其他转 str 后加到切片中</h3></li>
</ul>
<p><code>Append</code> 系列函数和 <code>Format</code> 系列函数的使用方法类似，只不过是将转换后的结果追加到一个切片中。</p>
<p>相比之下，入参多了一个 <code>[]string</code> 类型的数组，返回值是加完元素的数组。</p>
<p>函数原型：</p>
<p><code>func FormatBool(slice []string, b bool) []string</code></p>
<p><code>func FormatInt(slice []string, i int64, base int) []sting</code></p>
<p><code>func FormatUint(slice []string, i uint64, base int)  []string</code></p>
<p><code>func FormatFloat(slice []string, f float64, fmt byte, prec, bitSize int) []string</code></p>
<figure class="highlight go"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> main</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> (</span><br><span class="line">	<span class="string">&quot;fmt&quot;</span></span><br><span class="line">	<span class="string">&quot;strconv&quot;</span></span><br><span class="line">)</span><br><span class="line"></span><br><span class="line"><span class="function"><span class="keyword">func</span> <span class="title">main</span><span class="params">()</span></span> &#123;</span><br><span class="line">	<span class="comment">// 声明一个slice</span></span><br><span class="line">	b10 := []<span class="keyword">byte</span>(<span class="string">&quot;int (base 10):&quot;</span>)</span><br><span class="line"></span><br><span class="line">	<span class="comment">// 将转换为10进制的string，追加到slice中</span></span><br><span class="line">	b10 = strconv.AppendInt(b10, <span class="number">-42</span>, <span class="number">10</span>)</span><br><span class="line">	fmt.Println(<span class="keyword">string</span>(b10))</span><br><span class="line">	b16 := []<span class="keyword">byte</span>(<span class="string">&quot;int (base 16):&quot;</span>)</span><br><span class="line">	b16 = strconv.AppendInt(b16, <span class="number">-42</span>, <span class="number">16</span>)</span><br><span class="line">	fmt.Println(<span class="keyword">string</span>(b16))</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line"><span class="comment">//输出：</span></span><br><span class="line"><span class="comment">//int (base 10):-42</span></span><br><span class="line"><span class="comment">//int (base 16):-2a</span></span><br><span class="line"></span><br></pre></td></tr></table></figure>
<h2 id="参考链接"><a href="#参考链接" class="headerlink" title="参考链接"></a>参考链接</h2><p><strong><a target="_blank" rel="noopener" href="http://c.biancheng.net/view/5112.html"> Go语言strconv包：字符串和数值类型的相互转换</a></strong></p>
 
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<!-- Root element of PhotoSwipe. Must have class pswp. -->
<div class="pswp" tabindex="-1" role="dialog" aria-hidden="true">

    <!-- Background of PhotoSwipe. 
         It's a separate element as animating opacity is faster than rgba(). -->
    <div class="pswp__bg"></div>

    <!-- Slides wrapper with overflow:hidden. -->
    <div class="pswp__scroll-wrap">

        <!-- Container that holds slides. 
            PhotoSwipe keeps only 3 of them in the DOM to save memory.
            Don't modify these 3 pswp__item elements, data is added later on. -->
        <div class="pswp__container">
            <div class="pswp__item"></div>
            <div class="pswp__item"></div>
            <div class="pswp__item"></div>
        </div>

        <!-- Default (PhotoSwipeUI_Default) interface on top of sliding area. Can be changed. -->
        <div class="pswp__ui pswp__ui--hidden">

            <div class="pswp__top-bar">

                <!--  Controls are self-explanatory. Order can be changed. -->

                <div class="pswp__counter"></div>

                <button class="pswp__button pswp__button--close" title="Close (Esc)"></button>

                <button class="pswp__button pswp__button--share" style="display:none" title="Share"></button>

                <button class="pswp__button pswp__button--fs" title="Toggle fullscreen"></button>

                <button class="pswp__button pswp__button--zoom" title="Zoom in/out"></button>

                <!-- Preloader demo http://codepen.io/dimsemenov/pen/yyBWoR -->
                <!-- element will get class pswp__preloader--active when preloader is running -->
                <div class="pswp__preloader">
                    <div class="pswp__preloader__icn">
                        <div class="pswp__preloader__cut">
                            <div class="pswp__preloader__donut"></div>
                        </div>
                    </div>
                </div>
            </div>

            <div class="pswp__share-modal pswp__share-modal--hidden pswp__single-tap">
                <div class="pswp__share-tooltip"></div>
            </div>

            <button class="pswp__button pswp__button--arrow--left" title="Previous (arrow left)">
            </button>

            <button class="pswp__button pswp__button--arrow--right" title="Next (arrow right)">
            </button>

            <div class="pswp__caption">
                <div class="pswp__caption__center"></div>
            </div>

        </div>

    </div>

</div>

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/photoswipe@4.1.3/dist/photoswipe.min.css">
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/photoswipe@4.1.3/dist/default-skin/default-skin.min.css">
<script src="https://cdn.jsdelivr.net/npm/photoswipe@4.1.3/dist/photoswipe.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/photoswipe@4.1.3/dist/photoswipe-ui-default.min.js"></script>

<script>
    function viewer_init() {
        let pswpElement = document.querySelectorAll('.pswp')[0];
        let $imgArr = document.querySelectorAll(('.article-entry img:not(.reward-img)'))

        $imgArr.forEach(($em, i) => {
            $em.onclick = () => {
                // slider展开状态
                // todo: 这样不好，后面改成状态
                if (document.querySelector('.left-col.show')) return
                let items = []
                $imgArr.forEach(($em2, i2) => {
                    let img = $em2.getAttribute('data-idx', i2)
                    let src = $em2.getAttribute('data-target') || $em2.getAttribute('src')
                    let title = $em2.getAttribute('alt')
                    // 获得原图尺寸
                    const image = new Image()
                    image.src = src
                    items.push({
                        src: src,
                        w: image.width || $em2.width,
                        h: image.height || $em2.height,
                        title: title
                    })
                })
                var gallery = new PhotoSwipe(pswpElement, PhotoSwipeUI_Default, items, {
                    index: parseInt(i)
                });
                gallery.init()
            }
        })
    }
    viewer_init()
</script>

<!-- MathJax -->

<!-- Katex -->

<!-- busuanzi  -->


<script src="/js/busuanzi-2.3.pure.min.js"></script>


<!-- ClickLove -->

<!-- ClickBoom1 -->

<!-- ClickBoom2 -->


<script src="/js/clickBoom2.js"></script>


<!-- CodeCopy -->


<link rel="stylesheet" href="/css/clipboard.css">

<script src="https://cdn.jsdelivr.net/npm/clipboard@2/dist/clipboard.min.js"></script>
<script>
  function wait(callback, seconds) {
    var timelag = null;
    timelag = window.setTimeout(callback, seconds);
  }
  !function (e, t, a) {
    var initCopyCode = function(){
      var copyHtml = '';
      copyHtml += '<button class="btn-copy" data-clipboard-snippet="">';
      copyHtml += '<i class="ri-file-copy-2-line"></i><span>COPY</span>';
      copyHtml += '</button>';
      $(".highlight .code pre").before(copyHtml);
      $(".article pre code").before(copyHtml);
      var clipboard = new ClipboardJS('.btn-copy', {
        target: function(trigger) {
          return trigger.nextElementSibling;
        }
      });
      clipboard.on('success', function(e) {
        let $btn = $(e.trigger);
        $btn.addClass('copied');
        let $icon = $($btn.find('i'));
        $icon.removeClass('ri-file-copy-2-line');
        $icon.addClass('ri-checkbox-circle-line');
        let $span = $($btn.find('span'));
        $span[0].innerText = 'COPIED';
        
        wait(function () { // 等待两秒钟后恢复
          $icon.removeClass('ri-checkbox-circle-line');
          $icon.addClass('ri-file-copy-2-line');
          $span[0].innerText = 'COPY';
        }, 2000);
      });
      clipboard.on('error', function(e) {
        e.clearSelection();
        let $btn = $(e.trigger);
        $btn.addClass('copy-failed');
        let $icon = $($btn.find('i'));
        $icon.removeClass('ri-file-copy-2-line');
        $icon.addClass('ri-time-line');
        let $span = $($btn.find('span'));
        $span[0].innerText = 'COPY FAILED';
        
        wait(function () { // 等待两秒钟后恢复
          $icon.removeClass('ri-time-line');
          $icon.addClass('ri-file-copy-2-line');
          $span[0].innerText = 'COPY';
        }, 2000);
      });
    }
    initCopyCode();
  }(window, document);
</script>


<!-- CanvasBackground -->


    
  </div>
</body>
<script type="text/javascript">
if(!/Android|webOS|iPhone|iPod|BlackBerry/i.test(navigator.userAgent)){
  document.write('<script type="text/javascript" src="/js/FunnyTitle.js"><\/script>');
  document.write('<script type="text/javascript" src="/js/snow.js"><\/script>');
}
</script>
</html>